You searched for: “hebdomads”
hebdomad (s) (noun), hebdomads (pl)
1. A group of seven or seven days: "The hebdomads are regular features of calendars around the world."
"Monday to Sunday or Sunday to Saturday are the sequences of days in a hebdomad."2. Etymology: the number seven, from Late Latin hebdomas; which came from Greek hebdomos, "seventh"; from hepta, "seven".